Lifting jack



Patented June .16, 1925.'y

UNITED STATES CHARLES DAVIDSON' inzrwoon54 CONSIN.

x or RACINE, MANUFACTURING oo MrANY, on RACINE,

PATENT OFFICE.

WISCONSIN, ASSIGNOR T WALKER WISCONSIN, A CORPORATIOLI 0F WIS- LIFTIN G J ACK.

Application led August 20, 1924. Serial No. 733,131.

To nl." lr/zom if muy concor/1..'

Be it known that I, CHAnLI-:s D. ELLwoon, a citizen of the United States, residing at Racine, in the county of Racine and State of 'iseonsin, have invented certain new and height when lowered, in order to be placedv under thelow axle or other frame parts when the tire is collapsed, and capable oi a comparatively long lift to elevate the car above its normal driving height in order that the tire may be changed.

The jack here disclosed is oi the type employing a plurality of screw threaded members working one within another and each contributing its share to the total lift of the jack. As here shown, the jack comprises a pair of non-rotary screws, one of -which is stationary and the other vertically movable to lift the load. A hollow sleeve surrounds the two screws when the ]a ck 1s lowered, and has integral nuts formed 1n its two ends to engage the two screws respectively. Rotary means mounted in a fixed standard engages the outer surface of the:

sleeve to rotate same, and at the same time allows the sleeve to move vertically upon the stationary screw. A jack of this type is-diselosed in the eopending application of' Irwin E. Dearsley, Serial No. 732,040 filed August 14, 1924. The present application discloses improvements on the form of jack claimed in this copending application.

The particular' object of the present invention is to provide a jack of this type, wherein a plurality of driving means for the rotary sleeve are used, so as to provide a` balanced structure, which may be centered under the load, and which will tend to counteract the lateral stresses normally tending to force apart thedrivingmeans andthe sleeve. A further object is to provide an improved means for holding the inner screw against rotation.

Other objects and advantages of the invention will be readily apparent from the `following detailed description of an approved forni of the apparatus.

In the accompanying drawing: Fig. 1 is a side elevation of the jack. Fig. 2 is a central vertical Tsection on an enlarged scale, taken substantially on the "line 2?-2 .of Fig. 1.

Fig, 3 is a transverse section taken sub-v stantially on the line 3 3 of Fig. 1.

The standard 1 comprises a base portion 2, and an upright feentral hollow sleeve member 8 `which is exteriorly` Vthreaded throughout substantially its 'entire height. An inner screw member 4, having a loadsupporting cap 5 at its upper end,is freely slidable vertically through the hollow sleeve 3. An outer hollow cylindrical sleeve member 6 is formed with a nut 7 in its lower end Ymeshing with the stationary screw 3, and

a smaller nut 8 in its upper end meshing with the inner lifting screw 4. When the jack is in lowered or collapsed position the two screws 3 and 4 are nested within the outer sleeve v6. v

The outer cylindrical surface of sleeve 6 is provided with a series of longitudinally extending the axis of the sleeve and of the screw members nested therein. Mounted in suitable bearings in the oppositely disposed houslng extensionslO at the upper` end of the standard 1, are a pair of similar short inclned shafts 11 and 12, to which are secured the driving worms 13 and 14.- respectively. These wor11`1s13 and 14 mesh with the teeth 9 of sleeve 6 at diametrically opposite points, and as will` be noted in gear teeth 9 which are parallel to- Fig. 3 the worm 14.` is threaded oppositely i toworm 13, so that when both worms are rotated in the same direction they will oooperate in impartin rotary movement to the sleeve 6. A sma 1 spur. earVv 15 secured to the shaft 12, and a. simi ar gear- 16 secured to shaft 11, both` mesh witha larger spur gear 17 keyed tofav short driving shaft;

18 mounted in onelside ofthestandard.l Av socket- 19 secured to theouter upper endofj shaft 18 provides means for attaching any suitable Jform of removable handle by whieh the driving gear 17 may be rotated. Antifriction thrust bearings 20 are provided between the pinions 15 and 16, theworms 13 and 1i and the adjacent bearings for shafts 1l and 12 in the stationary standard; 'A bar or rod 21 is suspended by a pivot pin 22 between eais 23 at one side of the load-supporting cap 5. Bar 91 moves up and down betweenv apair o lined ears 2a at one side' of standard 1, and serves as a means to prevent rotation or" the inner screw Ll. If one should desire at any time to rotate the inner screw Il with relation to the other parts, it is only necessary to remove the rod 21 from between the locking ears 24.

Yln operation, a continuous rotation of driving gear 17 by means of the removable crank handle, will simultaneously rotate the two worms 13 and le at the same speed,

Iand due to the opposite directions of the f threads on ythese worms they will both cooperate to rotate the sleeve 6 in the desired direction. Since the side thrusts ol' these two'worins are 'toward one another, they tend to balance the stresses in the mechanism and keep the screws properly centered beneath the load. The symmetrical arrange- 'ment o vthe driving means at opposite sides ot the standard also balances the weight of the jack. The rotation of sleeve 6"\in the proper `direction will elevate it along thestationary screw the inner screw 4- which is held against rowith the stationary standardl 1, will be elevated with respect to the upwardly moving-sleeve 6' ofthe rotating nut the sleeve with the reverse rotation of will return the parts through the engagement S in the upper endof threads on screw il. A the operating handle to lowered position, with the two screws nested together and within the rotary sleeve S and Vstai'idard l.

Bi mounting the worms 13 and 14C 0n inclined axes, the necessarily inclined worm teeth will be vertically positioned on that side of the worm which meshes with the vertically extending teeth on sleeveI 9. Since the directions oi the threads on the two worms are reversed, the inner threads lof each will have the same inclination, there- 3. At the same time`,\

' tion, a lifting member interiorly thre fore with the two shaftsll and 12 in the.

`same inclined plane, both worms will mesh properly with the vertical threads of sleeve 9. This inclination ofthe worms, and the driving connections therefor, will also cause the operating handle to project upwardly at a convenient angle.

The gear reduction provided between the driving gear 17 and the piiiions l5 and 16, in addition to 'the large reduction provided by the worm and worm wheel drive and the screw drive between the standard and other, the lifting member having lifting members, to be elevated wit fort.

l claim:

l. A lifting jack comprising a stationary standard and a rotary lifting member having screw-threaded engagement with one another, the lifting member having longitudinally extending gear-teeth on its outer cylindrical surface, and a pair of driving worms mounted on the standard with their axes in the saine inclined plane and meshing with the teeth on the' lifting member at diameti'ically opposite points.

2. A lifting jack comprising a stationary standard and a rotary lifting member having screw-threaded engagement with one another, the lifting member having longitudinally extending gear-teeth on its outer cylindrical surface, a pair of driving worms mounted on the standard with their axes in the Same inclined plane and meshing with the teeth on the lifting member at diametrically opposite points, and means for simultaneously driving the worms from a. distance.

3. A. lifting jack comprising a stationary standard and a rotary lifting member having screw-threaded engagement with one anlongitudinally extending gear-teeth in its outer cylindrical surface, and rotary driving means mounted on the standard and enga ging the lifting member at diametrically op- ,poSite points to rotate the'lifting member and at the same time allow it to move vertically.

4. -A lifting jack comprising a stationary standard and a rotary lifting member having screw-threaded engagement with one another, the lifting member having longitudinally extending gea -teeth on its' outer cylindrical surface, and a pair of similar driving means mounted on the standard at opposite sides of the lifting member and engagiiig sameto rotate it while allowing it to move vertically.,

5. A lifting jack comprising a standardv having an exteriorly screw-threaded pol'- tdtfi to engage this portion and providedlop. its outer cylindrical surface with longitudinally extending gear-teeth, and a pair of oppositely threaded driving worms mounted on the standard 'with their axes in the same inclined lane and meshing with the teeth on the lifting member at diametrically opposite points.

6, A lifting jack comprising a standard having an enteriorly screw-threaded por- 'ion, a lifting member interiorly threaded- 'to engage this portion and provide on its outer (.-lylindrical surface with longitudinally extending gear-teeth, a. pair of threaded driving worms mounted on the lOO oppositely ISO il-tandard with their axes in the eame inrhned plane and meshing with the teeth on -the li lling member at diametrieally opposite and interior-ly threaded at opposite ends toV engage the :screw and standard respectively, and a pair ot similar driving means mounted on the standard and engaging the sleeve at. diametri lallv opposite points for rotating the sleeve.

h. li't'tin, t jaek Comprising a standard havinev a' screw-threaded portion, a load- Iunipol-ting' serew 'freelyv movable longitudinallv through the standard, means for holdine the screw against rotation, a hollow sleeve surrounding the sere Y and standard, and interior-ly threaded at opposite ends to engage the sei-ew and standard respectively, the outer surface ofthe Sleeve being providi'l with longitudinally extending gearteeth, aud a pair et driving,r worms mounted on the .-tandard with their axes in the saine inelined plane and meshinnT with the teeth at diametri :allv opposite points.

it. .t lifting jack comprising a standard having a serew-threaded portion, a loadi-uiiiiorting screw freely movable longitudinull)v through the standard, means for holdine the :serew against rotation, a holler.` sleeve surrounding the screw and standard,

and interiorly threaded at opposite ends to engage the screw and standard respectively, the outer surface. of the L#leere being provided with longitudinally extending gearteeth, a. pair ot" driving worms mounted on the standard with their axes in the Same-inelined plane and int-)Shing with the teeth at diainttriealhY opposite points, and means for simultaneouslyv rotating the two worms from a distance. t

l0. A lifting jack comprising a standard having a serew-thretuled portion, a loadsupporting screw Afreely ntovahle long gitudi-v nally through the etandard, inea-ns 'tor holding the screw against rotation, a hollow vsleeve surrounding the Screw and standard,

and interiorly threaded at opposite ende to engage the screw and Standard respectively,

'the outer' surlaee ot' the sleeve being provided with longitudinally extending gearteeth, a pair or oppositely threaded driving worms mounted on the standard with their axes in the same inclined plane and meshing with the teeth at diametrieally opposite points, a short, shaft. mounted in the standard and haring' an attaching member tor a removable handle, and gear Connections between the shaft. and the worms.

l1. A lifting jack comprising a standard, a littingjr screw longitudinally movable through the standard, and a har pivoted to the upper end of the screw, and removably slidahle between a pair o't ears at one eide of the standard, for holding the screw when desired against rotation while allowing it to move vertically.

I CHARLES DAVDSON ELLWUOD. 

